The word “interconnection” in very large-scale integrated circuits (VLSIs) means a metal line which connects the various electronic devices. The interconnecting metal lines are separated from the substrate by insulating layers, except on the contact area. Since the creation of the integrated circuit (IC) in 1960, aluminum (Al) or its alloy has become the primary material for interconnecting metal lines, and silicon dioxide has become the primary material for insulating layers.
Copper-based chips are semiconductor integrated circuits, usually microprocessors, which use copper for interconnections. Since copper is a better conductor than aluminum, chips using this technology can have smaller metal components, and use less energy to pass electricity through them. Together, these effects lead to higher-performance processors.